Apparatus for analyzing finely divided materials for size



larch 17, 1936. E T. T N 2,034,185

APPARATUS FOR ANALYZING- FINELY DIVIDED MATERIALS FOR SIZE Filed July 5,1933 m 5 mu i %M 8 7 9 .Q 9. m n v 5, 3 6 T old ATTY Patented Mar. .17,1936 UNITED STATES PATENT OFFICE APPARATUS FOR ANALYZING FINELY DIVIDEDMATERIALS FOR SIZE 4 Claims.

This invention relates to apparatus for obtaining a separation or a sizeanalysis of the particles in a finely divided product by subjecting itto fluid currents through a tube or a series of tubes of differentdiameters so that different sized particles will be separated. Theobject of the present invention is to devise simple means for causing acomplete breaking up of agglomerated particles so that an accurateseparation of the product will be obtained during each test.

I attain my object by providing the tube or each tube with an inlet inwhich a normally closed valve member is carried so that as thecontinuous current of air or other fluid is passed through each inletits valve member is opened. Finely divided solids suspended in the airmay thus flow past the valve member which is adapted not only to preventback flow of the solids from its tube but to assist in the breaking upof agglomerated particles so that a continuous current of air or otherfluid through the tube will carry the smaller particles therefrom. Byconnecting in series a number of tubes of progressively greater diameterthe said means prevents backflow of solids from one tube to itspreceding tube in addition to its other function and the current offluid carries the different sized particles to the different sized tubesin the series in one operation. The tubes are arranged in spacedrelationship and are so connected that the contents of each may-bereadily removed without disturbing the tubes.

The constructions are hereinafter more fully described and areillustrated in the accompanying drawing in which:

Fig. 1 is a diagrammatic view of my apparatus showing three tubesconnected in series;

Fig. 2 a detail in vertical section through the adjacent ends of twotubes showing theconaection therebetween in its'disconnected posi- Fig.3 a diagrammatic view of a receptacle connected with my apparatus; and

Fig. 4 a diagrammatic view of the thimble housing used when suctionmeans is employed.

In the drawing like numerals of reference indicate corresponding partsin the different figures.

I is a tube which may serve as a receptacle for receiving the finelydivided material to be analyzed. The bottom end of the tube is providedwith a substantially conicalinlet 2 having a ball 3 seated therein. Thelower end of the inlet 2 is counterbored at 4' to receive one end of apiece of tubing 5 the other end of which is connected by means offlexible tubing 6 with any suitable type of fluid supply means such as acompressed air line 1. To regulate the flow of air passing through thetube l, I provide a valve 8 in the line I and any suitable flow meterthe inlet 2 of the tube l such as the diaphragm gauge 9 and manometer Iwhich indicates the difference in pressure on opposite sides of thediaphragm 9 The tube i is carried on a standard II and supports a frameH which carries one or more tubes I, I which are connected in series ashereinafter described. The tube I is larger in diameter than the tube land the tube l is larger in diameter than the tube I so that thevelocity of the fluid passing through the 10 tubes is progressivelydecreased whereby different sized particles will be deposited in thedifferent sized tubes. The tubes I, I are provided with tapered ends andwith conical inlets 2, 2 having balls 3 3 seated therein and the lowerends of these inlets are counterbored at 4 4 to receive pieces of tubing5, 5. To the 1 outlet end of tube l is fitted a rubber stopper I2 inwhich the tubing 5* is slidable so that it may be moved axially towardsor away from the counterbore 4 in the inlet 2 of the tube I to permit itto be disconnected therefrom. If desired,.the lowered tubing and thestopper may then be lifted from the outlet end of the tube l.

imilarly the outlet ends of the tubes I, l are provided with stoppers I2I2 the tubing 5 being slidable in the stopper l2 to permit it to bedisconnected from the counterbore 4 in In the stopperl2 a piece of benttubing 5 carrying a porous thimble l3 may be inserted. This thimble isadapted to filter the solid particles or fractions from the air whichescape through the pores of the thimble.

If it be desired to draw the air through the v tubes I, l and I, thethimble l3 may be dispensed with and in this case the tubing 5 will beconnected with any suitable suction means such as an aspirator orinjector (not shown).

When suction is employed the preferred arrangement is to mount thethimble I3 in a housing I3 having an outlet 5* for connection with thesuction means.

Each of the tubes may be vibrated individually or a spring actuatedhammer l4 adapted to strike the frame ll may beused to vibrate all thetubes simultaneously. This hammer may be controlled by a motor drivencam l5 so that the tubes and also the balls 3, 3 and 3 will becontinuously vibrated during each test.

Assuming a sample of the finely divided product, which may be cement,has been placed in the tube I, the valve 8 opened to obtain the desiredflow of air and the hammer mechanism started, the operation is asfollows. The air pass- 55 ing through the tubing 5 forces the ball 3 offits seat in the inlet 2 and passes through the product in the tube Ithus carrying the small sized particles or fractions with it. Theseparticles which are of various sizes are thus suspended or ad in the airand pass withthe air through the tubing 5* to force the ball 3 of! itsseat in the inlet 2* of the tube I. As the tube I is larger in diameterthan the tube I, the velocity of the air with the fractions suspendedtherein is decreased during the passage of the air through the tube Iand the heavier particles carried by the air remain in the tube I. Theair and the particles still in suspension pass through the tubing 5 andthe heavier of these particles remain in the tube l The lightestparticles are carried with the air through the tubing 5 and deposited inthe thimble l3. The air is continuously supplied to the tube land thehammer i4 "is continuously vibratingthe tubes for a predetermined periodof time so that the particles of different sizes will be completelyseparated.

This separation is facilitated by the action of the valve member 3,which may be a ball or a plug of any suitable shape and weight, a steelball has been found satisfactory. The ball-is -continuous1y vibrated notonly by the current of air and particles passing through the inlet butby the motion imparted thereto by the vibration of each tube. The ballis thus moved longitudinally and laterally in the inlet and thus throughthe entering flow of particles which causes the separation of very fineparticles from one another and from coarser particles. Any

flocks of fine particles and the coarser particles In other words, theair in blowing through the product above the ball, thoroughly agitatesthe particles so that they are more or less in agitated suspension inthe lower part of the tube.

. Those particles whose settling rate is less than the upward travel ofthe air in the middle portion of the'tube pass on to the next tube. Manyparticles are adhering together and thus act as large particles which,as hereinbefore described, fall down the sides of the tube and are thenblown upwardly again. Thus in each tube there are a number of particlescontinually rubbing against one another and thus freeing themselves ofattached particles. The operation is continued 55until the" particleshave separated from one another and the undersized particles havebeenblown out of each tube.

Of course, it will be distinctly understood that any desired number oftubes may be used and that the greater the number in use the greater thenumber of different sized particles will be separated. That is to saythe number of tubes used in a test will of course be determined by thenumber of separations required of the product being tested. It isobvious that the tubing 5 with its thimble I! may be connected with thetube I or I and that any number of tubes may be used between the tube Iand the tubing 5.

When the particles have been thoroughly separated, the hammer I4 isstopped and the valve 8 closed. After suflicient time for the particlesto settle has elapsed; the thimble I3 is removed and the quantity of thecontents determined so that the proportion of this size of particle canbe I", l are removed therefrom by axially moving the tubings I. I, and5" through the stoppers I2. I

I! and l2 away from the counterbores 4, 4, 5'

so that receptacles may be positioned beneath the latter. By passing asuitable tool such as a stiff. piece of wire through a counterbore andthe lower end of the inlet, the ball therein will be forced upwardly sothat the particles in the tube will fall by gravity into thereceptaclebeneath the tube. The quantity of particles from each tube may then bedetermined in the same mannor as those from the thimble.

From this description it will be noted that the product is separatedinto the desired number of fractions in one operation and that thefractions may be readily removed from each of the tubes withoutdisconnecting the latter from the frame.

If desired, the tube I may be connected with a receptacle I! having anair line It across the bottom thereof for feeding the product to thetube. Any suitable valve or pinch cock may be used to close the portionit of the line l6 to prevent the air from within the tubing 6 escapingthrough the receptacle after the contents thereof have been blown intothe tube.

What I claim as my invention is:

1. Apparatus of the class described comprising a plurality of settlingtubes connected inseries; means for passing flnely divided solidssuspended in a fluid through the series of tubes, the tubes being ofprogressively greater diameter from the tube adjacent the fluid enteringend of the series towards the tube at the fluid outlet end,

the tubes having valve seats at their inlet ends;

and valve members adapted to engage the seats to prevent backflow ofsolids from the tubes and adapted to be raised off the seats by thepassage of the fluid therethrough.

' 2. Apparatus of the class described comprising a plurality of settlingtubes connected in series; means for passing finely divided solidssuspended in a fluid through the series of tubes, the tubes being ofprogressively greater diameter from the tube adjacent the fluid enteringend of the series towards the tube at the fluid outlet end; substan'tially conical inlets in the fluid entering ends of I the tubes; andvalve members adapted to be seated in the inlets to prevent backflow ofsolids lationship to one another, each tube having an outlet and aninlet; tubing slidablyfltted in the outlet of each tube adapted, whenextended, for connection with the adjacent inlet of the next tube; meansfor passing flnely divided solids suspended in a fluid through thetubes; and means in each inlet for preventing backflow of solidstherethrough.

4. Apparatus of the class described comprising a'plurality of settlingtubes carried in spaced relationship to one another, each tube having anoutlet and an inlet; tubing slidably fitted in the outlet of each tubeadapted. when extended, for connection with the adjacent inlet of thenext tubeiineans for passing finely divided solids suspended in a fluidthrough the tubes; and a ball seated in each inlet for preventingbackflow of solids therethrough.

HERBERT E. T. HAULTAIN.

